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Table 21 — Flywheel Data
*Refer to Fig. 17.
Table 22 — Flywheel — Compressor Dimensions
*Refer to Fig. 17.
BOOSTER COMPRESSORS FOR
REFRIGERANT 12, 22, 502, AND 507/404A
Booster Application Data —
The following data sup-
plements the single-stage compressor application data, and
adds information pertaining to booster application only. Refer
to the single-stage compressor data for all other information.
Rating Basis —
All booster ratings* are given in refriger-
ation effect and are based on:
1. Use of a liquid-suction heat interchanger. All liquid-
suction interchangers should have a bypass connection on
the liquid side so that adjustment can be made in event
that too much superheating of suction gas causes exces-
sive heating of compressor. This is especially true for
Refrigerant 22, which has a higher compression exponent
than Refrigerant 12.
2. The liquid refrigerant at Point A (Fig. 18) at satu-
ration temperature corresponds to booster discharge
pressure. This is often referred to as saturated inter-
mediate temperature.
This occurs when booster discharge gas is condensed in a
cascade (refrigerant-cooled) condenser, or when using an
open flash-type intercooler in a direct staged system.
When subcooling of liquid takes place in a closed-
type intercooler, it is not possible to bring liquid tempera-
ture down to saturated intermediate temperature because
of temperature difference required for heat transfer
through the liquid coil. In this case, the compressor rating
must be decreased 3% for each 10 degrees that liquid
temperature at Point A is above the saturated intermediate
temperature.
3. Use of only half of the standard number of suction valve
springs per cylinder. All 5F,H compressors are factory
assembled with the standard number of suction valve
springs; therefore, one-half of the springs per cylinder
must be removed in the field for booster applications.
4. Booster ratings are based on a 1750 rpm compressor
speed.
*R-507/404A ratings are similar to R-502.
“R” Factors —
In a multistage compression system, the
intermediate or high-stage compressor must have sufficient
capacity to handle the low-stage (booster) compressor load
plus heat added to refrigerant gas by a low-stage machine
during compression. Likewise, if an intermediate stage com-
pressor should be used, the high-stage compressor must have
sufficient capacity to handle the intermediate stage compressor
load plus heat added to the refrigerant gas by an intermediate
stage machine during compression.
To assist in the selection of higher stage compressors,
Table 23 presents “R” factors that depict approximate required
relationship between stages at various saturated temperature
conditions.
To determine the required capacity of a higher stage com-
pressor, multiply lower stage compressor capacity by the
proper “R” factor from Table 23. Any additional loads handled
at intermediate pressure must be added to this figure to arrive at
the total higher stage load.
Multistage System Pointers —
A staged system is
essentially a combination of 2 or more simple refrigerant
cycles. In combining 2 or more simple flow cycles to form a
staged system for low temperature refrigeration, 2 basic types
of combinations are common (Fig. 18).
DIRECT STAGING — Involves use of compressors, in
series, compressing a single refrigerant.
CASCADE STAGING — Usually employs 2 or more refrig-
erants of progressively lower boiling points. Compressed
refrigerant of low stage is condensed in an exchanger (cascade
condenser) that is cooled by evaporation of another lower
pressured refrigerant in the next higher stage.
Safety Factors —
Use of capacity safety factors in select-
ing booster compressors must be a matter of judgment when
making selection.
Factors that have a bearing on satisfactory compressor
selections are: accuracy of load estimate, amount of safety
factor included in the total load, degree of importance of meet-
ing specified capacity at given condition, temperature level of
operation and magnitude of refrigeration load. All of the
factors must be recognized when considering the use of a
capacity safety factor in selecting a booster compressor.
Figure 19 presents reasonable safety factors for use in selec-
tion of booster compressors. These can be employed when it is
not desired to establish a factor based on selector’s judgment.
FLYWHEEL
PACKAGE
NUMBER
FLYWHEEL
MODEL
WIDTH
A (in.)*
OD
C (in.)*
PITCH
DIAM
D (in.)*
GROOVES
(No. and
Type)
5F20-394
5F20-1053 1
3
/
4
8.0 7.5 2-B
5F30-394
5F30-1053 2
1
/
2
8.0 7.5 3-B
5F40-394
5F40-1054 2
1
/
2
10.0 9.5 3-B
5F60-394
5F60-1054 3
1
/
8
10.0 9.5 4-B
5H40-394
5H40-1104 3
3
/
8
11.75 11.0 3-C
5H60-394
5H60-1104 5
3
/
8
11.75 11.0 5-C
5H80-394
5H80-1104 6
3
/
8
11.75 11.0 6-C
5H120-394
5H120-1104 9
3
/
8
11.75 11.0 9-C
COMPRESSOR
MODEL
FLYWHEEL
MODEL
DIMENSIONS
F (in.)*
5F20
5F20-1053 6
7
/
8
5F30
5F20-1053 8
5
/
8
5F30-1053 8
3
/
4
5F40
5F40-1054 10
5
/
8
5F60
5F40-1054 11
5
/
8
5F60-1054 11
3
/
4
5H40
5H40-1104 13
1
/
4
5H60-1104 13
11
/
16
5H60
5H40-1104 14
5H60-1104 14
7
/
16
5H80
5H40-1104 20
5H60-1104 20
7
/
16
5H80-1104 18
9
/
16
5H120-1104 21
5
/
16
5H120
5H60-1104 20
11
/
16
5H120-1104 21
9
/
16
GROOVES
F TO C OF FLYWHEEL
L
C OF COMPRESSOR
L
A
D
C
Fig. 17 — Flywheel